Available evidence on the occurrence of Vulnerable marine ecosystems (VMEs), fishing activity in relation to VMEs, and spatial management options to minimise the risk from fishing activities to VMEs

Overview

For the purpose of this assessment, evidence of VME occurrence is aggregated at the scale of individual 0.05 x 0.05 degrees C-square cells (hereafter termed C-square) where VME habitats or indicator taxa are assumed to be homogeneously distributed. Similarly, fishing effort information is aggregated at the scale of C-squares.

The VME polygon methodology is described in the ACOM technical guidelines based on WKVMEBM (ICES 2022).

Bottom fishing (static and mobile) is the single most important human-induced pressure on the seafloor in this area (see ICES ecosystem overviews).

The VME database contains 212 VME habitat and 932 VME indicator c-squares in this area (based on the 2021 VME data call). This information has been collected through various gear types and survey methods.

New VME data

New VME habitat and indicator records were submitted and quality checked. This resulted in 49 new VME Habitat c-squares and 212 new VME Index c-squares; 41 index High, 46 index Medium and 125 index Low.

No new VME physical elements were added to the area.

Most new VME Habitat and Index C-squares are outside previous defined VME polygons.

Map of VMEs

Information on VME Habitat and Index C-squares and the spatial distribution of static and mobile bottom-fishing

** **

Key to map layers

Layer Description
EEZ boundaries Exclusive Economic Zone. Area beyond and adjacent to the territorial sea, extending to a distance of no more than 200 nautical miles from the baselines from which the breadth of the territorial sea is measured.
Depth zone 400-800 m Seafloor at 400 – 800 m depth.
Existing VME c-sqrs Existing VME class of each c-square displayed as VME habitat (bona fide VME that represent unequivocal evidence for a VME occurrence), and high, medium and low VME index scores, indicating the likelihood of encountering a VME in the assessed grid cells.
New/Updated VME c-sqrs VME class in each c-square added or with an updated class based on latest VME data call, displayed as VME habitat (bona fide VME that represent unequivocal evidence for a VME occurrence), and high, medium and low VME index scores, indicating the likelihood of encountering a VME in the assessed grid cells.
EU fishable domain Area with presence of bottom gears within 400-800m depth between 2009-2011 (EU waters only).
Fished area (S+M) Area with presence of bottom fishing in the latest 5 years by static and mobile gears (all depths > 200).
Reference fished area (S) Area with presence of static bottom fishing in 2009-2011 (all depths > 200).
Fished area (S) Area with presence of static bottom fishing in the latest 5 years (all depths > 200).
Reference fished area (M) Area with presence of mobile bottom fishing in 2009-2011 (all depths > 200).
Fished area (M) Area with presence of mobile bottom fishing in the latest 5 years (all depths > 200).
Existing VME Physical Elements Existing seabed topographic features (e.g. banks, coral mounds, seamounts), extracted from EMODnet .
New/Updated VME Physical Elements Additional seabed topographic features (e.g. e.g. banks, coral mounds, seamounts) from new data sources or updated  delineations of existing features.

Overlap VME c-sqs and fishing

Summary table of new and cumulative VME evidence and overlap with static gear and/or mobile fishing gears at the scale of C-squares.
Number of VME/VME element c-squares
Total existing
New/updated in 2021
Assessed area
Areas fished between 2018-2020
Assessed area
In defined VME polygons
All Mobile gears Static gears M + S gears All S1O1 S1O2 S2O1 S2O2 S1O2+S2O1
VME habitat
200-400m 4 5 4 6 3
400-800m 64 67 68 76 27 0 5 3 2 0
>800m 78 17 23 28 19
VME index Medium and High
200-400m 12 15 15 16 5
400-800m 81 64 69 73 60 1 13 1 1 0
>800m 110 17 17 23 22
VME index Low
200-400m 95 134 133 134 40
400-800m 211 274 260 278 81 1 1 1 1 0
>800m 59 9 5 10 4
VME physical elements
Seamounts 3644 70 25 84 0 0 0 0 0 0
Banks 275 0 6 6 0 0 0 0 0 0
Coral mounds 168 53 44 65 0 0 0 0 0 0
Mud volcanoes 28 11 0 11 0 0 0 0 0 0

VME polygon options

The new data submissions lead to several new and updated VME polygons in the area.

The VME polygons will reduce the fishable domain between 400-800m depth with xx-xx% (depending on the scenarios/options).

Map of updated VME polygons

Update of the VME polygons following the scenarios/options.

** **

Key to map layers

Layer Description
EEZ boundaries Exclusive Economic Zone. Area beyond and adjacent to the territorial sea, extending to a distance of no more than 200 nautical miles from the baselines from which the breadth of the territorial sea is measured.
Depth zone 400-800 m Seafloor at 400 – 800 m depth.
Existing VME polygons scenario 1 option 1 Existing polygons delineating continuous areas of VME (containing c-squares with VME habitats or a High and Medium VME Index, see Scenario options).
New VME polygons scenario 1 option 1 Updated delineation of continuous areas of VME (containing c-squares with VME habitats or a High/Medium VME Index) based on the most recent VME data call.
Existing VME polygons scenario 1 option 2 Existing polygons delineating continuous areas of VME (Option 1 + selected VME elements associated with any VME records, see Scenario options).
New VME polygons scenario 1 option 2 Updated delineation of continuous areas of VME (Option 1 + selected VME elements associated with any VME records).
Existing VME polygons scenario 2 option 1 Existing polygons delineating continuous areas of VME (containing c-squares with VME habitats or a High/Medium VME Index, or a Low VME Index if adjacent to higher index VMEs - and fishing pressure is low see Scenario options).
New VME polygons scenario 2 option 1 Updated delineation of continuous areas of VME (containing c-squares with VME habitats All VME habitats, or a High and/ Medium VME Index, or a. Low VME Index: only if adjacent to higher index VMEs and Low VME Index in C-squares with low and fishing pressure is low).
Existing VME polygons scenario 2 option 2 Existing polygons delineating continuous areas of VME (containing c-squares with VME habitats or a High/Medium/VME Index where fishing pressure is low see Scenario options).
New VME polygons scenario 2 option 2 Updated delineation of continuous areas of VME (containing c-squares with VME habitats or a High/Medium/VME Index where fishing pressure is low).
EU fishable domain Area with presence of bottom gears between 2009-2011 within 400-800m depth (EU waters only).

Scenario options

Scenario Option Description of C-square closures Management implication
1 1 C-squares with VME habitats as well as C-squares with high and medium VME indices, regardless of fishing activity. C-squares with a low VME index only included if adjacent to C-squares with medium to high VME indices. Prioritizes identification of VME polygons where they “are known to occur”, and where they “are likely to occur”, regardless of fishing activity.
1 2 Scenario 1–Option 1 + C-squares that contain selected VME physical elements (banks, seamounts, coral mounds, mud volcanoes) associated with any VME indicator species records. Prioritizes identification of VME polygons where they “are known to occur” and “are likely to occur”, as well as elements that are known to frequently contain VMEs, regardless of fishing activity.
2 1 As Scenario 1–Option 1 but includes low VME index C-squares if MBCG fishing pressure is also low (SAR < 0.43). This option preferentially includes Low Index c-sqrs. where these occur outside the more highly fished areas. Prioritizes identification of VME polygons where they “are known to occur” or “ are likely to occur”, and includes C squares with low VME index where cumulative fishing activity is also low and significant adverse impacts (SAIs) by past fishing are less likely, this therefore offers potential VME protection at low cost to the fishery and highest potential protection of VMEs in the fishing footprint.
2 2 C-squares including all VME habitats, high, medium and low VME Index C-squares but excluding C-squares with high cumulative MBCG fishing pressure (SAR > 0.43). This option effectively only considers VME Index (of any category) in areas outside of relatively high fishing effort areas. Prioritizes identification of VME polygons where they are known or likely to occur, but excludes areas that have been intensely fished and where VMEs are therefore potentially damaged by past trawl fishing. By leaving heavily fished areas open, there is reduced impact on fishing activities.

Scenario outcomes and risks

Summary table of scenario outcomes and associated risk to VMEs.
Scenario 1 Option 1 Scenario 1 Option 2 Scenario 2 Option 1 Scenario 2 Option 2 Scenario 1 Option 2 + Scenario 2 Option 1
VME polygon description All VME habitats, High and Medium VME Index. Low VME Index: only if adjacent to medium or high Index VMEs. Option 1 + selected VME elements (banks, seamounts, coral mounds, mud volcanoes) associated with any VME records. All VME habitats, High and Medium VME Index. Low VME Index: only if adjacent to higher index VMEs and Low VME Index in C-squares with low fishing pressure All VME habitats, High, Medium and Low VME Index excluding C-squares with high fishing pressure (SAR > 0.43) Scenario 2, Option 1 + selected VME elements (banks, seamounts, coral mounds, mud volcanoes) associated with any VME records.
VME polygon outcomes
% of fishable domain identified as VME polygon 13.1 13.9 15.3 9.8 16.1
% of VME polygon protected by existing VME fishery closures NA NA NA NA NA
Number of VME polygons and their average areal extent (size) 139 (208.7 km2) 139 (416 km2) 161 (206.5 km2) 144 (173.9 km2) 161 (385 km2)
Number (and average size) of large VME polygons in upper 25th percentile of the size distribution 7 (1081 km2) 1 (27344.5 km2) 9 (988.9 km2) 10 (657.6 km2) 1 (27344.5 km2)
Risk to VME NA NA NA NA NA
Fishery consequences
% of effort per year by static gear (400-800m depth) overlapping with VME polygons (average annual effort between 2018 to 2020) NA NA NA NA NA
% of fished area (400-800m depth) by static gear overlapping with VME polygons between 2018 to 2020 9.8 9.8 11.1 6.2 11.1
% of SAR by mobile gear (400-800m depth) overlapping with VME polygons (average annual SAR between 2018 to 2020) 6.1 6.1 7.6 2.1 7.6
% of fished area (400-800m depth) by mobile gear overlapping with VME polygons between 2018 to 2020 7.8 7.8 9.3 4.8 9.3

Interpretation of results

Brief interpretation of results (max ½ page) [A verbal reference to factors in ecology (realism), management and/or fishing practices which are important in understanding the indicated results and ranked closure options. Also if there are any noticable trendsm and if these changes are related to the specific locations or not. Special emphasis on certainty of data in terms of the VME index, elements, and other supporting information.

Limitations and caveats relate to issues concerning the provision of vessel data and their interpretation, the scale at which the data are used and considered to be informative, and the information base used in the definition and evaluation of spatial closure scenarios.

Read me

This scientific assessment of occurrence of vulnerable marine ecosystems (VMEs), fishing activity in the vicinity of VMEs, as well as spatial management options consists of this assessment and a data product, consisting of spatial data layers (as shapefiles) of the fishable domain and proposed VME polygons based on the different scenarios/options. The spatial data layers are accompanied with a csv-file with the coordinates. Each VME polygon csv-file also indicates the VME habitat, VME indicator and VME physical element data present, as well as the VME habitat and index C-squares.

The data and scripts that produced the assessment are available here: https://github.com/ices-taf/VME-Advice

Sources and references

ICES 2022 WKVMEBM
ICES 2021 VME datacall
ICES 2021 VMS datacall